Apparatus and method for sensing rotary switch handling direction of monitor

ABSTRACT

An apparatus and method for sensing a rotary switch handling direction of a monitor is disclosed, in which a simple configuration can be obtained and accuracy in sensing a handling direction can be enhanced. The apparatus for sensing a rotary switch handling direction of a monitor includes a rotary switch for outputting voltage levels varied correspondingly depending on a user&#39;s handling direction, and a microcomputer for storing the voltage levels output from the rotary switch and comparing the voltage levels with a previously stored voltage change/handling direction table to determine a handling direction of the rotary switch. Since the handling direction is sensed by the voltage level difference for respective contacts, it is possible to exactly sense the handling direction and to relatively obtain a simple configuration.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a monitor, and moreparticularly, to an apparatus and method for sensing a rotary switchhandling direction of a monitor.

[0003] 2. Background of the Related Art

[0004] Generally, with development of computer software, high picturequality is required for a monitor. However, the monitor has severalproblems, such as balancing error, focusing error, and color purityerror, in controlling and adjusting a screen. With a large sized screenof a monitor, the above problems are becoming more serious.

[0005] Accordingly, a monitor is provided with a compensating means thatcompensates such problems. As an example of the compensating means, aplurality of switches for adjusting a screen are provided in apredetermined region of the monitor. When the switches are provided tocompensate errors for a plurality of screen adjusting modes, problemsarise in that it is not easy for a user to handle a desired switch andthe screen may incorrectly be adjusted.

[0006] To solve such problems, there has been provided a rotary switchthat can select desired screen adjusting modes by allowing a user torotate the switch. A related art rotary switch will be described withreference to FIGS. 1 to 3.

[0007] As shown in FIG. 1, the related art rotary switch includes afixed disc 22 and a rotary disc 24. The rotary disc 24 overlaps thefixed disc 22 and rotates around a common shaft 26 relative to the fixeddisc 22. [06] The fixed disc 22 includes a plurality of conductor pads28 arranged to have the same angle around the common shaft 26. Therotary disc 24 includes two switches SWA and SWB. The switches SWA andSWB are fixed on the rotary disc 24 and arranged at angles with eachother at a predetermined angle along a circular trace of the rotary disc24.

[0008] A circuit configuration of the related art rotary switch will bedescribed with reference to FIG. 2.

[0009] As shown in FIG. 2, the circuit of the related art rotary switchincludes switches SWA and SWB, a resistor R1, a capacitor C, and aswitch SWU. Each of the switches SWA and SWB has one end supplied with apower source of 5 V through a resistor R2 and the other end commonlygrounded. The resistor R1 and the capacitor C are connected in seriesbetween both ends of the respective switches SWA and SWB to form eachloop of the switches SWA and SWB. The switch SWU is commonly groundedwith the other ends of the switches SWA and SWB and has one endconnected with a CPU of the monitor. The circuit of the related artrotary switch further includes a pulse generator (not shown) forrespectively generating predetermined pulses when the switches SWA andSWB are in contact with the conductor pads 28.

[0010] The operation of sensing a handling direction of the related artrotary switch will now be described.

[0011] If a user rotates the rotary disc 24 in a predetermineddirection, the switches SWA and SWB are in contact with the conductorpads 28 of the fixed disc 22. As a result, as shown in FIG. 3, outputpulses ‘PA’ and ‘PB’ are generated by the pulse generator and thenoutput through each switch.

[0012] At this time, since the switches SWA and SWB have a fixedrelation position, as shown in FIG. 3, the output pulse ‘PA’ isgenerated by rotation of the rotary disc 24. Then, the output pulse ‘PB’is generated at a time difference ‘t1-t2’ relative to the user's rotarydisc handling speed.

[0013] Meanwhile, if the user rotates the rotary disc 24 in a directionopposite to the predetermined direction, the output pulse ‘PB’ isgenerated and then the output pulse ‘PA’ is generated at a timedifference relative to the user's rotary disc handling speed. Therefore,it is possible to sense the user's handling direction according to thephase difference between the output pulses ‘PA’ and ‘PB’.

[0014] The related art rotary switch has several problems.

[0015] First, in sensing the handling direction, the rotary switch andits linked circuits have complicated circuit configurations.Furthermore, since the handling direction of the rotary switch is sensedby the phase of the pulses, it is likely that error operation may occurdue to delay of the phase.

SUMMARY OF THE INVENTION

[0016] Accordingly, the present invention is directed to an apparatusand method for sensing a rotary switch handling direction of a monitorthat substantially obviates one or more problems due to limitations anddisadvantages of the related art.

[0017] An object of the present invention is to provide an apparatus andmethod for sensing a rotary switch handling direction of a monitor inwhich a simple configuration can be obtained and accuracy in sensing ahandling direction can be enhanced.

[0018] Additional advantages, objects, and features of the inventionwill be set forth in part in the description which follows and in partwill become apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

[0019] To achieve these objects and other advantages and in accordancewith the purpose of the invention, as embodied and broadly describedherein, an apparatus for sensing a rotary switch handling direction of amonitor includes a rotary switch for outputting voltage levels variedcorrespondingly depending on a user's handling direction, and amicrocomputer for storing the voltage levels output from the rotaryswitch and comparing the voltage levels with a previously stored voltagechange/handling direction table to determine a handling direction of therotary switch.

[0020] In another aspect of the present invention, in a method forsensing a rotary switch handling direction of a monitor having a rotaryswitch and a microcomputer, the rotary switch having variable outputlevels depending on a user's handling direction, the method includes thesteps of successively reading out and storing, at a microcomputer, thevoltage levels output from the rotary switch depending on the user'srotary switch handling direction for predetermined number of times, andcomparing the stored voltage levels of the rotary switch, at themicrocomputer, with a previously stored voltage change/handlingdirection table to sense a handling direction of the rotary switch.

[0021] It is to be understood that both the foregoing generaldescription and the following detailed description of the presentinvention are exemplary and explanatory and are intended to providefurther explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiment(s) of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings:

[0023]FIG. 1 is a diagram showing a structure of a related art rotaryswitch for adjusting a screen of a monitor;

[0024]FIG. 2 is a circuit diagram showing a circuit configuration ofFIG. 1;

[0025]FIG. 3 is an output waveform of FIG. 2;

[0026]FIG. 4 is a diagram showing an apparatus for sensing a rotaryswitch handling direction of a monitor according to the presentinvention;

[0027]FIG. 5 is a diagram showing a configuration of a rotary switch ofFIG. 4; and

[0028]FIG. 6 is an output waveform of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

[0029] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings.

[0030] As shown in FIG. 4, an apparatus for sensing a rotary switchhandling direction of a monitor according to the present inventionincludes a rotary switch 30 for outputting voltage levels variedcorrespondingly depending on a user's handling direction, and amicrocomputer 40 for sensing a handling direction of the rotary switch30 depending on the voltage levels output from the rotary switch 30.

[0031] In a circuit configuration of the apparatus, resistors R1-R4 areserially connected in turn between a power source terminal of 5 V and aground terminal. A fixed contact ‘a’ is connected with a node betweenthe resistor R1 and the power source terminal, a fixed contact ‘b’between the resistor R1 and the resistor R2, a fixed contact ‘c’ betweenthe resistor R2 and the resistor R3, and a fixed contact ‘d’ between theresistor R3 and the resistor R4. A detecting contact 34 is connectedwith the microcomputer 40.

[0032] Voltages having different levels are applied to the respectivefixed contacts ‘a’, ‘b’, ‘c’, and ‘d’ in proportional to resistancevalues of corresponding voltage dividing resistors R1-R4. For example,since the fixed contact ‘a’ remains without passing through anyresistor, 5 V is applied thereto. 4 V is applied to the fixed contact‘b’, and 3V is applied to the fixed contact ‘c’.

[0033] At this time, the rotary switch 30, as shown in FIG. 5, includesa plurality of fixed contacts 33 fixed in a round shape to maintain apredetermined interval and angle, a rotary shaft 33, a detecting contact34 rotated around the rotary shaft 33 in accordance with a user's rotaryswitch handling and contacted with the fixed contacts 32, a shaft 35 fordirectly rotating the rotary shaft 33 in engagement with the user'srotary switch handling so as to rotate the detecting contact 34.

[0034] The operation of sensing the aforementioned rotary switchhandling direction will be described below. TABLE 1 Fixed a b c dcontact Applying 5 4 3 2 voltage (V)

[0035] First, voltage values applied to the respective contacts aredefined as Table 1.

[0036] The user rotates the rotary switch 30 to select a desired menuamong screen adjusting menus displayed on the screen. Thus, thedetecting contact 34 is rotated in a predetermined direction, i.e., auser's handling direction, by the operation of the shaft 35 mechanicallyengaged with the rotary shaft 33 within the rotary switch 30.

[0037] For example, if the user continues to rotate the rotary switch 30in a right direction, as shown in FIG. 6, the voltage levels input tothe microcomputer 40 through the detecting contact 34 are reduced in theorder of 5 V→4 V→3V→2V and again returned to 5 V. These steps arerepeated.

[0038] Meanwhile, if the user continues to rotate the rotary switch 30in a left direction, as shown in FIG. 6, the voltage levels input to themicrocomputer 40 through the detecting contact 34 are reduced in theorder of 2 V→3 V→4 V→5 V and again returned to 2 V. These steps arerepeated.

[0039] Accordingly, if the voltage levels are changed in such a way as‘5→4’, ‘4→3’,‘3→2’, or ‘2→5’, it is noted that the user has rotated therotary switch 30 in a right direction. If the voltage levels are changedin such a way as ‘5→2’, ‘2→3’, ‘3→4’, or ‘4→5’, it is noted that theuser has rotated the rotary switch 30 in a left direction. TABLE 2 Firstoutput of Second output of detecting contact detecting contact Handlingdirection 5 4 Right 4 3 Right 3 2 Right 2 5 Right 5 2 Left 2 3 Left 3 4Left 4 5 Left

[0040] In the present invention, a table based on the principle of ahandling direction according to the voltage change, e.g., a voltagechange/handling direction table as shown in Table 2, is stored in amemory or external memory of the microcomputer 40.

[0041] Subsequently, successive outputs of the detecting contact 34 areread out twice and then stored. That is to say, a first output of thedetecting contact 34 is read out and then stored in a first memoryregion and a second output of the detecting contact 34 is read out andthen stored in a second memory region.

[0042] The first and second outputs of the detecting contact 34 arerespectively compared with the voltage change/handling direction tableso that a handling direction of the rotary switch 30 is sensed.

[0043] Once the handling direction of the rotary switch 30 is sensed,the microcomputer 40 moves to a menu in a corresponding direction amongthe screen adjusting menus displayed on the screen so that a resultselected by the user is displayed.

[0044] In the embodiment of the present invention, while four fixedcontacts have been described, it is apparent that the number of thefixed contacts can be increased and the handling direction of the rotaryswitch can accurately be sensed if a difference exists in apredetermined voltage level applied to the respective fixed contacts,e.g., a voltage of 0.5 V or greater (minimum voltage level to preventrecognition error of the microcomputer).

[0045] As aforementioned, the apparatus and method for sensing a rotaryswitch handling direction of a monitor has the following advantages.

[0046] Since the handling direction is sensed by the voltage leveldifference for the respective contacts, it is possible to exactly sensethe handling direction and to relatively obtain a simple configuration.

[0047] The forgoing embodiments are merely exemplary and are not to beconstrued as limiting the present invention. The present teachings canbe readily applied to other types of apparatuses. The description of thepresent invention is intended to be illustrative, and not to limit thescope of the claims. Many alternatives, modifications, and variationswill be apparent to those skilled in the art.

What is claimed is:
 1. An apparatus for sensing a rotary switch handlingdirection of a monitor comprising: a rotary switch for outputtingvoltage levels varied correspondingly depending on a user's handlingdirection; and a microcomputer for storing the voltage levels outputfrom the rotary switch and comparing the voltage levels with apreviously stored voltage change/handling direction table to sense ahandling direction of the rotary switch.
 2. The apparatus of claim 1,wherein the rotary switch includes: a plurality of resistors seriallyconnected between a power source (5 V) terminal and a ground terminal; aplurality of fixed contacts to which different voltage levels areapplied, respectively connected with a node between the respectiveresistors or a node between the power source terminal and the resistor;and a detecting contact rotated by a user's rotary switch handling, foroutputting a corresponding voltage level to the microcomputer in contactwith the fixed contacts.
 3. The apparatus of claim 1, wherein the outputvoltages sequentially increase during right rotation of the rotaryswitch while the output voltages sequentially decrease during leftrotation of the rotary switch.
 4. A method for sensing a rotary switchhandling direction of a monitor having a rotary switch and amicrocomputer, the rotary switch having variable output voltage levelsdepending on a user's rotary handling direction, the method comprisingthe steps of: successively reading out and storing, at a microcomputer,the voltage levels output from the rotary switch depending on the user'srotary switch handling direction for predetermined number of times; andcomparing the stored voltage levels of the rotary switch, at themicrocomputer, with a previously stored voltage change/handlingdirection table to sense a handling direction of the rotary switch. 5.The method of claim 4, wherein the predetermined number of times in thestep of reading out and storing the voltage levels are at least twotimes or more.
 6. The method of claim 4, wherein the voltagechange/handling direction table includes at least two voltage level datafor each period of respective directions (right side/left side) duringrotation of the rotary switch.